public class Test {
    public static int add(int x, int y) {
        return x + y;
    }

    public static double add(double x, double y) {
        return x + y;
    }

    public static double add(double x, double y, double z)
    {
        return x + y + z;
    }

    public static int fac(int n){
        if(n == 1){
            return 1;
        }

        return n*fac(n-1);
    }


    public static void main(String[] args) {
        /*int ret1 = add(10, 20);
        double ret2 = add(3.14, 6.28);
        double ret3 = add(3.6, 2.5, 9.6);*/

        int ret = fac(5);
        System.out.println(ret);

    }
}
